1/* pidfile.c
2 *
3 * Functions to assist in the writing and removing of pidfiles.
4 *
5 * Russ Dill <Russ.Dill@asu.edu> Soptember 2001
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22#include <sys/types.h>
23#include <sys/stat.h>
24#include <fcntl.h>
25#include <unistd.h>
26#include <errno.h>
27#include <string.h>
28#include <stdio.h>
29
30#include "debug.h"
31
32int pidfile_acquire(char *pidfile)
33{
34	int pid_fd;
35	if (pidfile == NULL) return -1;
36
37	pid_fd = open(pidfile, O_CREAT | O_WRONLY, 0644);
38	if (pid_fd < 0) {
39		LOG(LOG_ERR, "Unable to open pidfile %s: %s\n",
40		    pidfile, strerror(errno));
41	} else {
42		lockf(pid_fd, F_LOCK, 0);
43	}
44
45	return pid_fd;
46}
47
48
49void pidfile_write_release(int pid_fd)
50{
51	FILE *out;
52
53	if (pid_fd < 0) return;
54
55	if ((out = fdopen(pid_fd, "w")) != NULL) {
56		fprintf(out, "%d\n", getpid());
57		fclose(out);
58	}
59	lockf(pid_fd, F_UNLCK, 0);
60	close(pid_fd);
61}
62
63
64void pidfile_delete(char *pidfile)
65{
66	if (pidfile) unlink(pidfile);
67}
68
69
70